[RocksDB] [Performance Branch] Trivia build fix
[RocksDB] [Performance Branch] Trivia build fix

Summary: make release complains signed unsigned comparison.

Test Plan: make release

Reviewers: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14661

Applied-Duality/rocksdb,facebook/rocksdb,tizzybec/rocksdb,rDSN-Projects/rocksdb.replicated,caijieming-baidu/rocksdb,skunkwerks/rocksdb,hobinyoon/rocksdb,rDSN-Projects/rocksdb.replicated,luckywhu/rocksdb,flabby/rocksdb,alihalabyah/rocksdb,wskplho/rocksdb,NickCis/rocksdb,Applied-Duality/rocksdb,geraldoandradee/rocksdb,vashstorm/rocksdb,anagav/rocksdb,lgscofield/rocksdb,skunkwerks/rocksdb,tschottdorf/rocksdb,norton/rocksdb,skunkwerks/rocksdb,mbarbon/rocksdb,rDSN-Projects/rocksdb.replicated,rDSN-Projects/rocksdb.replicated,lgscofield/rocksdb,ylong/rocksdb,biddyweb/rocksdb,rDSN-Projects/rocksdb.replicated,alihalabyah/rocksdb,ryneli/rocksdb,Andymic/rocksdb,wskplho/rocksdb,mbarbon/rocksdb,hobinyoon/rocksdb,JohnPJenkins/rocksdb,wenduo/rocksdb,caijieming-baidu/rocksdb,msb-at-yahoo/rocksdb,tsheasha/rocksdb,siddhartharay007/rocksdb,Andymic/rocksdb,facebook/rocksdb,RyanTech/rocksdb,IMCG/RcoksDB,virtdb/rocksdb,IMCG/RcoksDB,amyvmiwei/rocksdb,SunguckLee/RocksDB,mbarbon/rocksdb,zhangpng/rocksdb,OverlordQ/rocksdb,temicai/rocksdb,JoeWoo/rocksdb,facebook/rocksdb,dkorolev/rocksdb,wlqGit/rocksdb,wskplho/rocksdb,RyanTech/rocksdb,kaschaeffer/rocksdb,zhangpng/rocksdb,sorphi/rocksdb,JohnPJenkins/rocksdb,Andymic/rocksdb,OverlordQ/rocksdb,caijieming-baidu/rocksdb,ryneli/rocksdb,vmx/rocksdb,Andymic/rocksdb,RyanTech/rocksdb,flabby/rocksdb,facebook/rocksdb,ryneli/rocksdb,flabby/rocksdb,wat-ze-hex/rocksdb,siddhartharay007/rocksdb,zhangpng/rocksdb,dkorolev/rocksdb,kaschaeffer/rocksdb,wlqGit/rocksdb,zhangpng/rocksdb,msb-at-yahoo/rocksdb,amyvmiwei/rocksdb,makelivedotnet/rocksdb,Applied-Duality/rocksdb,IMCG/RcoksDB,temicai/rocksdb,ryneli/rocksdb,fengshao0907/rocksdb,Andymic/rocksdb,jalexanderqed/rocksdb,sorphi/rocksdb,siddhartharay007/rocksdb,siddhartharay007/rocksdb,luckywhu/rocksdb,rDSN-Projects/rocksdb.replicated,wenduo/rocksdb,vashstorm/rocksdb,hobinyoon/rocksdb,JackLian/rocksdb,alihalabyah/rocksdb,OverlordQ/rocksdb,IMCG/RcoksDB,tizzybec/rocksdb,vashstorm/rocksdb,Applied-Duality/rocksdb,biddyweb/rocksdb,msb-at-yahoo/rocksdb,amyvmiwei/rocksdb,ylong/rocksdb,JohnPJenkins/rocksdb,SunguckLee/RocksDB,tschottdorf/rocksdb,Applied-Duality/rocksdb,alihalabyah/rocksdb,luckywhu/rocksdb,ylong/rocksdb,JackLian/rocksdb,JoeWoo/rocksdb,flabby/rocksdb,vmx/rocksdb,bbiao/rocksdb,amyvmiwei/rocksdb,JohnPJenkins/rocksdb,norton/rocksdb,IMCG/RcoksDB,OverlordQ/rocksdb,tizzybec/rocksdb,fengshao0907/rocksdb,tsheasha/rocksdb,wat-ze-hex/rocksdb,wskplho/rocksdb,amyvmiwei/rocksdb,fengshao0907/rocksdb,Vaisman/rocksdb,skunkwerks/rocksdb,ryneli/rocksdb,ylong/rocksdb,virtdb/rocksdb,JackLian/rocksdb,temicai/rocksdb,makelivedotnet/rocksdb,jalexanderqed/rocksdb,anagav/rocksdb,lgscofield/rocksdb,dkorolev/rocksdb,tsheasha/rocksdb,IMCG/RcoksDB,RyanTech/rocksdb,alihalabyah/rocksdb,SunguckLee/RocksDB,kaschaeffer/rocksdb,Vaisman/rocksdb,bbiao/rocksdb,alihalabyah/rocksdb,virtdb/rocksdb,OverlordQ/rocksdb,wenduo/rocksdb,norton/rocksdb,vashstorm/rocksdb,JoeWoo/rocksdb,SunguckLee/RocksDB,jalexanderqed/rocksdb,rDSN-Projects/rocksdb.replicated,norton/rocksdb,hobinyoon/rocksdb,SunguckLee/RocksDB,jalexanderqed/rocksdb,zhangpng/rocksdb,JackLian/rocksdb,msb-at-yahoo/rocksdb,fengshao0907/rocksdb,NickCis/rocksdb,NickCis/rocksdb,makelivedotnet/rocksdb,tschottdorf/rocksdb,kaschaeffer/rocksdb,makelivedotnet/rocksdb,bbiao/rocksdb,fengshao0907/rocksdb,geraldoandradee/rocksdb,ylong/rocksdb,kaschaeffer/rocksdb,virtdb/rocksdb,temicai/rocksdb,vmx/rocksdb,anagav/rocksdb,Andymic/rocksdb,SunguckLee/RocksDB,vmx/rocksdb,kaschaeffer/rocksdb,amyvmiwei/rocksdb,skunkwerks/rocksdb,biddyweb/rocksdb,ryneli/rocksdb,Vaisman/rocksdb,hobinyoon/rocksdb,JackLian/rocksdb,vashstorm/rocksdb,sorphi/rocksdb,virtdb/rocksdb,mbarbon/rocksdb,bbiao/rocksdb,lgscofield/rocksdb,zhangpng/rocksdb,SunguckLee/RocksDB,amyvmiwei/rocksdb,tschottdorf/rocksdb,wenduo/rocksdb,Applied-Duality/rocksdb,flabby/rocksdb,wat-ze-hex/rocksdb,sorphi/rocksdb,Vaisman/rocksdb,vashstorm/rocksdb,msb-at-yahoo/rocksdb,skunkwerks/rocksdb,luckywhu/rocksdb,norton/rocksdb,dkorolev/rocksdb,biddyweb/rocksdb,mbarbon/rocksdb,dkorolev/rocksdb,tschottdorf/rocksdb,wat-ze-hex/rocksdb,hobinyoon/rocksdb,tizzybec/rocksdb,JoeWoo/rocksdb,ryneli/rocksdb,vmx/rocksdb,lgscofield/rocksdb,Vaisman/rocksdb,wat-ze-hex/rocksdb,SunguckLee/RocksDB,wat-ze-hex/rocksdb,tschottdorf/rocksdb,wlqGit/rocksdb,sorphi/rocksdb,fengshao0907/rocksdb,Andymic/rocksdb,JohnPJenkins/rocksdb,kaschaeffer/rocksdb,facebook/rocksdb,norton/rocksdb,norton/rocksdb,biddyweb/rocksdb,bbiao/rocksdb,caijieming-baidu/rocksdb,dkorolev/rocksdb,luckywhu/rocksdb,jalexanderqed/rocksdb,mbarbon/rocksdb,wenduo/rocksdb,ylong/rocksdb,tizzybec/rocksdb,JoeWoo/rocksdb,siddhartharay007/rocksdb,wat-ze-hex/rocksdb,wat-ze-hex/rocksdb,OverlordQ/rocksdb,NickCis/rocksdb,geraldoandradee/rocksdb,NickCis/rocksdb,bbiao/rocksdb,tsheasha/rocksdb,sorphi/rocksdb,biddyweb/rocksdb,JoeWoo/rocksdb,JohnPJenkins/rocksdb,caijieming-baidu/rocksdb,facebook/rocksdb,hobinyoon/rocksdb,wenduo/rocksdb,wlqGit/rocksdb,virtdb/rocksdb,zhangpng/rocksdb,temicai/rocksdb,wskplho/rocksdb,jalexanderqed/rocksdb,siddhartharay007/rocksdb,biddyweb/rocksdb,geraldoandradee/rocksdb,flabby/rocksdb,caijieming-baidu/rocksdb,JackLian/rocksdb,wlqGit/rocksdb,lgscofield/rocksdb,anagav/rocksdb,tsheasha/rocksdb,anagav/rocksdb,siddhartharay007/rocksdb,IMCG/RcoksDB,RyanTech/rocksdb,fengshao0907/rocksdb,ylong/rocksdb,bbiao/rocksdb,wenduo/rocksdb,facebook/rocksdb,tizzybec/rocksdb,Vaisman/rocksdb,makelivedotnet/rocksdb,Andymic/rocksdb,RyanTech/rocksdb,norton/rocksdb,geraldoandradee/rocksdb,makelivedotnet/rocksdb,OverlordQ/rocksdb,NickCis/rocksdb,alihalabyah/rocksdb,facebook/rocksdb,msb-at-yahoo/rocksdb,tsheasha/rocksdb,temicai/rocksdb,tizzybec/rocksdb,skunkwerks/rocksdb,anagav/rocksdb,JackLian/rocksdb,tsheasha/rocksdb,geraldoandradee/rocksdb,mbarbon/rocksdb,lgscofield/rocksdb,vashstorm/rocksdb,Vaisman/rocksdb,flabby/rocksdb,caijieming-baidu/rocksdb,wskplho/rocksdb,RyanTech/rocksdb,vmx/rocksdb,sorphi/rocksdb,wlqGit/rocksdb,virtdb/rocksdb,geraldoandradee/rocksdb,wlqGit/rocksdb,vmx/rocksdb,luckywhu/rocksdb,bbiao/rocksdb,NickCis/rocksdb,vmx/rocksdb,Applied-Duality/rocksdb,luckywhu/rocksdb,wskplho/rocksdb,wenduo/rocksdb,JohnPJenkins/rocksdb,jalexanderqed/rocksdb,makelivedotnet/rocksdb,tsheasha/rocksdb,JoeWoo/rocksdb,anagav/rocksdb,dkorolev/rocksdb,hobinyoon/rocksdb,temicai/rocksdb